[gdb] Further fix "value is not available" with debug frame

In commit 2aaba744467 ("[gdb] Fix "value is not available" with debug frame")
I fixed a case in frame_unwind_register_value where using "set debug frame on"
caused an "info frame" command to abort, reporting a "value is not available"
error, due to the tpidruro register being unavailable.

Subsequently, commit bbb12eb9c84 ("gdb/arm: Remove tpidruro register from
non-FreeBSD target descriptions") removed the unavailable register, which
caused a progression on test-case gdb.base/inline-frame-cycle-unwind.exp.

While investigating the progression (see PR python/31437), I found that the
"debug frame" output of the test-case (when reverting commit bbb12eb9c84)
showed a smilar problem:
...
Python Exception <class 'gdb.error'>: value is not available^M
...
that was absent without "debug frame".

Fix this likewise in fetch_lazy_register, and update the test-case to check
for the exception.

Furthermore, I realized that there's both value::entirely_available and
value::entirely_unavailable, and that commit 2aaba744467 handled the case
of !entirely_available by printing unavailable.

Instead, print:
- "unavailable" for entirely_unavailable, and
- "partly unavailable" for !entirely_unavailable && !entirely_available.

Tested on x86_64-linux and arm-linux.

diff --git a/gdb/frame.c b/gdb/frame.c
index d3c4c9640aac088d7cc4087115991831def41324..f1f97040ff0c3716cdd87d8f19d5d90f97a2f28c 100644 (file)
--- a/gdb/frame.c
+++ b/gdb/frame.c
@@ -1315,9 +1315,7 @@ frame_unwind_register_value (const frame_info_ptr &next_frame, int regnum)
 
          if (value->lazy ())
            gdb_printf (&debug_file, " lazy");
-         else if (!value->entirely_available ())
-           gdb_printf (&debug_file, " unavailable");
-         else
+         else if (value->entirely_available ())
            {
              int i;
              gdb::array_view<const gdb_byte> buf = value->contents ();
@@ -1328,6 +1326,10 @@ frame_unwind_register_value (const frame_info_ptr &next_frame, int regnum)
                gdb_printf (&debug_file, "%02x", buf[i]);
              gdb_printf (&debug_file, "]");
            }
+         else if (value->entirely_unavailable ())
+           gdb_printf (&debug_file, " unavailable");
+         else
+           gdb_printf (&debug_file, " partly unavailable");
        }
 
       frame_debug_printf ("%s", debug_file.c_str ());

diff --git a/gdb/testsuite/gdb.base/inline-frame-cycle-unwind.exp b/gdb/testsuite/gdb.base/inline-frame-cycle-unwind.exp
index 82632757f139291c19b66f6bd5a2f9674ef1abe1..85e3cc32f0e3265a88bcba0ecbc1ece5d293e953 100644 (file)
--- a/gdb/testsuite/gdb.base/inline-frame-cycle-unwind.exp
+++ b/gdb/testsuite/gdb.base/inline-frame-cycle-unwind.exp
@@ -131,9 +131,14 @@ with_test_prefix "cycle at level 1" {
 gdb_test "maint flush register-cache" \
     "Register cache flushed\\." ""
 gdb_test_no_output "set debug frame 1"
+set ok 1
 gdb_test_multiple "bt" "backtrace with debugging on" {
     -re "^$gdb_prompt $" {
-       pass $gdb_test_name
+       gdb_assert { $ok } $gdb_test_name
+    }
+    -re "Python Exception <class 'gdb.error'>: \[^\r\n\]*\r\n" {
+       set ok 0
+       exp_continue
     }
     -re "\[^\r\n\]+\r\n" {
        exp_continue

diff --git a/gdb/value.c b/gdb/value.c
index a2b2721d183a181712a5690f5f873d7b68cc00f5..7ddfeb7c7286f5f0ca953641b1161d4cd89d112a 100644 (file)
--- a/gdb/value.c
+++ b/gdb/value.c
@@ -4014,9 +4014,6 @@ value::fetch_lazy_register ()
        }
       else
        {
-         int i;
-         gdb::array_view<const gdb_byte> buf = new_val->contents ();
-
          if (new_val->lval () == lval_register)
            gdb_printf (&debug_file, " register=%d", new_val->regnum ());
          else if (new_val->lval () == lval_memory)
@@ -4026,11 +4023,21 @@ value::fetch_lazy_register ()
          else
            gdb_printf (&debug_file, " computed");
 
-         gdb_printf (&debug_file, " bytes=");
-         gdb_printf (&debug_file, "[");
-         for (i = 0; i < register_size (gdbarch, regnum); i++)
-           gdb_printf (&debug_file, "%02x", buf[i]);
-         gdb_printf (&debug_file, "]");
+         if (new_val->entirely_available ())
+           {
+             int i;
+             gdb::array_view<const gdb_byte> buf = new_val->contents ();
+
+             gdb_printf (&debug_file, " bytes=");
+             gdb_printf (&debug_file, "[");
+             for (i = 0; i < register_size (gdbarch, regnum); i++)
+               gdb_printf (&debug_file, "%02x", buf[i]);
+             gdb_printf (&debug_file, "]");
+           }
+         else if (new_val->entirely_unavailable ())
+           gdb_printf (&debug_file, " unavailable");
+         else
+           gdb_printf (&debug_file, " partly unavailable");
        }
 
       frame_debug_printf ("%s", debug_file.c_str ());